Although the availability of a wide variety of image sensors makes it possible to supply an image processing system with a wealth of information in the form of a large number of images of the same scene or object, actually correlating the information content in such images may be a significant challenge to the user. This difficulty arises from the fact that the images may be, and particularly in the case of spaceborne or airborne terrestrial imaging systems, can be expected to be derived from sensors having different observation and collection geometries, as well as different wavelength sensitivities.
In order to facilitate exploitation of information contained in multiple images of a scene, it is often an a priori requirement that the images be mutually registered or aligned. Unfortunately, this registration requirement is not easily fulfilled when the images are derived from diverse types of sensors having different observation and collection geometries. Indeed, it is often the case that multiple images of the same terrestrial area are obtained at different times (seasons) of the year.